Semiconductors devices such as memory devices reside in many computer and electronic products. Memory devices store data. Input data is stored into a memory device in a write operation. Output data is outputted from the memory device in a read operation.
Most memory devices have data (input/output) pins and data strobe pins. The data pins carry the input and output data to and from the memory device. The data strobe pins carry timing information of the data.
Some memory devices have two separate sets of data strobe pins: write data strobe pins and read data strobes pins. The write data strobe pins carry timing information of the input data. The read data strobe pins carry timing information of the output data.
In most cases, the write data strobe pins are unused during the read operation; and the read data strobe pins are unused during the write operation.
Leaving some pins unused in some operations wastes resources.